I'd suspect a more "normal" problem causing the no-start.
First- is the timing belt intact? Someone needs to remove the oil cap and peek inside while the engine is cranked. The cam should be visible, rotating.

2nd: fuel pump relays on all these cars are a problem. Remove and re-solder internally or replace yours. There's probably a date code on it, and they rarely survive longer than 8 years. It's in the middle of the fuse/relay panel, and you remove the ashtray, cig lighter trim, 2 screws and the coin tray to pull it out. It's white, 1X2 inches, PN is 3523608. #1 cause for a no-start.

3) The crank sensor (aka rpm sensor, aka impulse sensor) that provides the ignition and ECU with pulses is due for replacement. Any original one is going to leave you stranded. They're $30 to $50 depending on source. It is just behind the head, mounted to the top of the trans bell housing, and has what looks like a cable-tv wire coming from it. Should have a white or yellow paint band on that wire. They are getting to be a common failure these days as they age.

4. While you're in the fusebox, there is a Radio Suppression Relay that the ignition circuit is also powered by. See the FAQ for location. Now that I think of it, a 91 may have an electric cooling fan- if so, it's under the hood.

e} good luck!
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Rob Bareiss, New London CT ::: '87 244DL/M47- 229K, 88 744GLE- 218K, 82 245T-181K Also responsible for the care and feeding of: 88 745GLE, 231K, 87 244DL, 239K, 88 245DL, 246K